However, as is my custom, I do not delete email, so I have accumulated tens of thousands of messages. The maildir format used by my mail system, wherein each mail folder is a filesystem folder and each message is a file, does not scale well to this volume. As a result, my mail tools all suck wind while CPU and disk usage on my mail server spike, just to get new messages or move some email to a different folder. It sucks.

Maildir isn’t exactly new, and was conceived as huge improvement over the even more amazingly shitty UNIX mail storage technology, mbox, in which each folder is a file and each message in the folder is concatenated to the file.

However, it being the 21st century and all, it seems somewhat obvious to everyone except developers of UNIX mail systems that a high-performance relational database is a good way to store email. Exchange has had an RDBMS backend since 2000 at least; Notes as I understand it has had it since inception.

Sadly, the UNIX mail world has a while to wait for this particular cutting edge innovation. The DBMail project has the right idea, but it’s very immature, and doesn’t even support SSL yet.

So, unless I go off the reservation and embrace a proprietary system like Zimbra, I would appear to be screwed.